This invention relates to controlling the connection of redundant power supplies to loads.
Power supply redundancy is conventionally dealt with by connecting two identical supplies in parallel to a power bus. Only the supply with the higher output voltage setting will deliver power on the bus to the loads. However, a short circuited output in either of the two supplies will overload the power bus and result in the loss of regulated power to the loads.
This problem is circumvented in a second prior art approach by adding an isolation diode in the output of each supply. However, the resulting diode power loss is objectionable for systems with large load currents. In addition, the diode drop will result in poor load regulation for low output voltages, unless remote load sensing is used.